#ifndef __lucasCommon_H#define __lucasCommon_Hstatic const double pi = 3.14159265358979323846;inline static double square(int a){    	return a * a;    }inline static void allocateOnDemand( IplImage **img, CvSize size, int depth, int channels ){    	if ( *img != NULL )	return;            	*img = cvCreateImage( size, depth, channels );    	if ( *img == NULL )        	{        		fprintf(stderr, "Error: Couldn't allocate image.  Out of memory?\n");        		exit(-1);        	}    }#endif